Natatolana nammuldi Bruce, 1986

Keable, Stephen J., 2006, Taxonomic Revision of Natatolana (Crustacea: Isopoda: Cirolanidae), Records of the Australian Museum 58 (2), pp. 133-244 : 202-203

Natatolana nammuldi Bruce, 1986

Natatolana nammuldi Bruce, 1986: 113 , figs. 77, 78.– Springthorpe & Lowry, 1994: 53.– Brusca et al., 1995: 82.– Bruce et al., 2002: 152.

Natatolana wullunya Bruce, 1986: 120 , fig. 83.–Springthorpe & Lowry, 1994: 66.– Brusca et al., 1995: 82.

Type material of Natatolana nammuldi . Holotype: ♀, 20.2 mm, NMV J1718 (not examined) . Paratypes: NMV J1719–1722 , J1753 (not examined); AM P32363–32365 (examined) ; USNM 190722 (not examined). Type locality of Natatolana nammuldi : Western Port , Victoria, Australia, 38°27'S 145°14'E .

Type material of Natatolana wullunya . Holotype: ♀, 11.3 mm, AM P30364 (examined). Type locality of Natatolana wullunya : off Sydney , NSW, Australia, 33°58'S 151°29'E, 150 m.

Material examined. New South Wales: 7, AM P47287, east of Coffs Harbour , 30°17.49'S 153°13.90'E, 45.4 m, 11–12 Aug. 1993, SEAS NSW-873; 53, AM P47288, between Lookout Point and Seahorse Shoals, Twofold Bay, 37°5.6'S 149°56.6'E, baited trap, unknown substrate, probably sediment, 30 m, J. Lowry & S. Keable, 28–29 Nov. 1988, NSW-392 . Tasmania: series from east of Fortescue Bay , 43°09.37'S 145°13.6'E, 300 m, 16–18 April 1993; 8, AM P47289, SEAS TAS-361; 28, AM P47290, SEAS TAS-361; 24, AM P47291, SEAS TAS-378 .

Diagnosis. Interocular furrow: moderately developed, distinct but not extending across the cephalon. Frontal lamina: lateral margins medially constricted. Antenna: c. 0.27–0.3× as long as body, reaching to posterior of pereonite 2. Coxal plates: furrows moderately developed, on all coxae. Pleonite 4: apex slightly rounded. Pleotelson: broad or narrow, length 0.90–1.00× basal width; anterodorsal depression absent; anterolateral margins almost straight and angling posteriorly toward the midline, or convex; posterolateral margins straight, markedly angled to anterolateral margins and meeting at an acute angle or convex; apex not produced, lateral margins converging smoothly to a point or produced into a small point; with 6– 8 RS. Pereopods 2–3: propodus without RS on palm. Pereopod 7: basis broad, width 0.58× length; distance between anterior margin and medial carina greater than between posterior margin and medial carina; posterior margin with setae on entire length. Penes: absent. Pleopod 2 appendix masculina: extending subequal with tip of endopod, 0.99× length of endopod; margins very slightly curved laterally; slender; apex recurved, bent slightly medially, bluntly rounded. Uropods: exopod slightly shorter than endopod, 0.87–0.9× the length of the endopod; lateral margin with or without RS (present in type material).

Variation. In all samples specimens with eight robust setae on the pleotelson were most abundant but specimens with six robust setae were also common. In a sample from eastern Tasmania ( AM P47291) forty percent of the specimens have four robust setae on the uropod endopod medial margin and the remainder has five. Two specimens from this sample were found to have three robust setae on the lateral margin of the uropod endopod as in the type material of N. nammuldi , whereas all other specimens examined have only two. The specimens in another sample from the same locality in eastern Tasmania ( AM P47290) lack robust setae on the uropod exopod lateral margin, however, these could not be otherwise distinguished from specimens in the same sample ( AM P47289, eight specimens) that have two to four robust setae on this margin .

Size. Adults from c. 11.3 mm to c. 27 mm, largest manca 7 mm.

Remarks. Bruce (1986) discussed the differences between Natatolana nammuldi and N. woodjonesi and N. wowine . Differences between N. nammuldi and N. wullunya , however, were not discussed. Bruce (1986) separated N. wullunya from all other species principally by its narrow frontal lamina. He also discussed other differences between N. wullunya , N. arrama and N. woodjonesi , including the shape of the frontal lamina, clypeus, pereopod 7, and number of robust setae on the pleotelson and lateral margin of the uropod exopod. Both N. nammuldi and N. wullunya were originally reported only from female specimens and single localities. For N. wullunya only a single specimen was recorded.

Comparison of type material of Natatolana nammuldi and N. wullunya indicates that any difference in the shape of the frontal lamina is relatively minor. The only other differences that could be found between the two nominal taxa are that the type material of N. nammuldi has eight robust setae on the pleotelson (except AM P32365 which has seven [six in N. wullunya ]); five robust setae on the uropod endopod medial margin (four in N. wullunya ); three robust setae on the uropod endopod lateral margin (two in N. wullunya ); and four robust setae on the uropod exopod lateral margin (three in N. wullunya ). The lateral margin of the uropod endopod is also slightly sinuate in the types of N. nammuldi (convex in N. wullunya ) but this appears to be related to the larger size of the specimens. In the other material examined here, variations between the two extremes were found within samples, although most material had only two robust setae on the uropod endopod lateral margin.

Therefore, Natatolana nammuldi and N. wullunya appear to be synonymous as reported in Bruce et al. (2002) based on the unpublished thesis of Keable (1996). Natatolana nammuldi is recognized as the objective senior synonym because it has page precedence, a more accessible type locality and more type specimens than N. wullunya . Further material from the type localities of N. nammuldi and N.wullunya would help to confirm that the variation noted here is intra-specific.

Distribution and ecology. Australia: off Coffs Harbour/off Sydney/in Twofold Bay, New South Wales; Western Port,

Victoria; off the east coast of Tasmania. At depths of 8.1–300 m (the holotype of N. wullunya was collected from 150 m and the type material of N. nammuldi from c. 8.1 m). Scavenger.